The present invention relates to small-size motors and, more particularly to stepping and servo motors that may be used in a motor vehicle to adjust various vehicle parts, and to methods of manufacturing and using the same.
Small-size motors, particularly step motors and servomotors, are being used increasingly, in some cases in considerable numbers, for the adjustment or setting of system elements such as are found in motor vehicles. This use partially takes place under extreme conditions, for example, in automobile construction, where the motors must operate reliably under considerable temperature fluctuations in a dusty, dirty, damp and even wet environment. Usually, such small-size motors, particularly step motors, are controlled by a central electronic control system which generally requires an at least four-conductor cable connection from the central electronic system to each motor and is therefore connected with considerable expenditures. In addition, a considerable number of connecting points are required, and these points are frequently the cause of interruptions and, therefore, of operational failures.
It is an object of the present invention, therefore, to simplify control and cabling and, therefore, to make the motor operationally more reliable.
It is a further object of the invention to configure the motor such that it operates reliably in a continuous manner also under extreme operating conditions, for example, in the engine compartment of a motor vehicle.
According to a presently contemplated embodiment of the present invention, these objects have been achieved by arranging an electronic control system directly with the motor. As a result, a secure and direct connection is achieved between the electronic system and the motor without any cabling, and the cabling can be simplified in that the individual motors are controlled by a central electronic control system by way of a databus and may be supplied with energy by way of parallel or joint conductors. Instead of a large number of cables which are laid in a star shape from the electronic control system to the individual motors, a single cable, which in general has no more than three leads, can be guided along the shortest path from the central electronic control system to all motors.
The electronic control system is preferably housed in a plastic housing which is firmly connected with the coil form of the motor. This housing is preferably provided with an end element which is not sealed hermetically and which, although it prevents dust and dirt from entering into the housing compartment, permits a sufficient vapor exchange in order to permit condensed water formed in the housing to evaporate and discharge.